Multi-application robotized platform for neurosurgery and resetting method

ABSTRACT

The invention relates to a multi-application robotized platform for neurosurgery, comprising: a planning console comprising processing means that can especially receive and process digital images; a positioning robot arm comprising a plurality of arm segments, one of which is terminal and proximal and the other is terminal and distal, said segments being interconnected by articulated elements, the terminal distal arm segment comprising a receiving element arranged in such a way as to receive tools, and the robot arm being guided by the planning console; at least one video image recording means able to record images of the anatomical region to be processed, said means being electrically connectable to the processing means of the planning console, and able to be positioned and fixed to the receiving element of the distal arm segment in a removable manner; tools, instruments and others suitable for being positioned and fixed to the receiving element of the terminal distal arm segment in a removable manner; means for observing pre-operating and per-operating images, said means being electrically connected to the planning console for receiving video signals therefrom relating to the images to be displayed, and/or to the image recording means. The invention also relates to a method ensuring an improved resetting of the anatomical region to be processed in relation to its digital model using said platform.

TECHNICAL FIELD

This invention is related to the field of materials used in medicine andmore specifically in neurosurgery. It relates in particular to amulti-application robotized platform for neurosurgery and the associatedimplementation method.

STATE OF THE PRIOR ART

It is known that the practicing of neurosurgery requires the use of anever increasing number of dedicated surgical materials and equipment.

Thus, stereotaxic frames are used in particular for tumoral biopsies orthe accurate positioning of stimulation electrodes. A disadvantage ofthese frames is that they do not lend themselves well, or at all, toopen surgery. Besides their size, another disadvantage residesessentially in that they require a firm anchorage in the bones of thecranium.

Also known are robots that can be used instead of stereotaxic frames.Also known, from the state of the art, are neuro-navigation systemsoffering a solution applicable to open surgery. These systems permit thedetection of anatomical structures based on a pre-operating imaginggiven by a scanner, by a magnetic resonance imaging (MRI) apparatus orthe like, and on a three-dimensional localization system, comprising forexample several light sources attached to the instrument, emitting inthe infrared range.

These systems comprise in addition one or more cameras capable ofperceiving the infrared and of emitting a signal that will be processedby an appropriate computer capable of calculating the data regarding thepositions and orientations in space of the surgical instrument such asthe position of the tip of the latter.

Typically, before the carrying out of the imaging, the skull of thepatient is equipped with radio-opaque markers, in the form of pastilles,designed to be affixed next to the skin. The obtained digital images aretransferred to a memory bank of the computer. With the help of thesurgical instrument or of a specific instrument the surgeon brings thetip of this instrument in contact with each of the radio-opaque markers.Thus, the position of the instrument can be located with respect to thepreviously obtained digitized medical images. In this way, during thesurgical action in particular, the image of the instrument and itsposition can be superimposed to the digital images in view of displayingthem jointly on a display screen.

The neuro-navigation systems are in particular used for the detectionand resection of cerebral tumors.

Also known are surgical microscopes used as visualization tools duringopen neurosurgical actions (ex.: corticectomy).

The surgical applications described above and the equipment associatedthereto represent a considerable portion of the routine practice inneurosurgery.

However, the plurality of the pieces of equipment and their specificitypertaining to a type of neurosurgical application are disadvantageous inthe hospital logistical management, and conflicting with the objectivesof flexibility and versatility of the operating theater.

Another disadvantage specific to neuro-navigation resides in thepossibilities of errors of resetting between the established digitalmodel, the patient, and the tool. This is related essentially to thefact that radio-opaque pastilles are affixed on the skin, which remainsa moving element, and not implanted fixedly in the cranial bones.

For the positioning of these radio-opaque markers, the practitionertries however to avoid any invasive procedure despite the risk of lossof resetting precision due to the involuntary displacement of one of themarkers.

Also known from the state of the art is a robotized guiding device forsurgical tools. Such a tool is in particular described in patentapplication FR 2 871 363. This robotized device includes a robot arm,means for collecting anatomical marks with the help of the robot arm,means for processing these anatomical marks and means for automaticpositioning of an instrument for guiding a surgical tool, this guidinginstrument being carried by the robot arm.

This guiding device is not provided with means for recording images ofthe field of operation or with specific means for visualization of thefield of operation.

This device does not meet the objective pursued by this invention.

EXPOSITION OF THE INVENTION

This invention aims at solving the problems mentioned above byproviding, on the one hand, a multi-application solution substitutingall devices listed above and, on the other hand, a method aiming at animproved resetting of the digital model of the anatomical region to beprocessed with the patient and the surgical tool.

To this end, the multi-application robotized platform for neurosurgeryis essentially characterized in that it comprises:

a planning console comprising processing means capable, in particular,of receiving and processing digital images,

a positioning robot arm comprising a plurality of arm segments, one ofwhich is terminal and proximal and the other is terminal and distal,said segments being interconnected by articulated elements and theterminal distal arm segment comprising a receiving element arranged insuch a way as to receive tools, instruments, and the like, said robotarm being guided by the planning console,

at least one video image recording means capable of recording images ofthe anatomical region to be processed, said recording means beingelectrically connectable to the processing means of the planningconsole, and said recording means being capable of being positioned andremovably fixed to the receiving element of the terminal distal armsegment,

tools, instruments, and the like designed to be positioned and removablyfixed to the receiving element of the terminal distal arm segment,

means for displaying pre-operating and per-operating images, said meansbeing electrically connected to the planning console for receiving videosignals therefrom relating to the images to be displayed, and/or to theimage recording means.

According to another feature of the invention, the positioning robot armhas at least six degrees of freedom i.e. three translations and threerotations thanks to which the tool or the instrument and the like thatit carries can be positioned and oriented in space in all possible ways.

According to another feature of the invention, the robot arm comprises aforce sensor and is designed to operate according to a mode in which auser can move the robot arm manually by seizing it by its terminalportion. The robot arm then operates in a cooperative mode.

According to another feature of the invention, the planning console isequipped with a control screen and with a communication interfacedesigned to receive operating planning parameters from a user.

Thanks to these arrangements, the processing means can take intoconsideration the operating planning parameters in order to control thetrajectory of the positioning robot and in particular the trajectory ofthe tool or of the instrument, or of the image recording means that itcarries.

Thus, the cranial entry point and the target point in the cervical mass,for example, can be furnished to the platform thanks to a simple andfriendly graphical interface.

The communication interface can, for example, be in the form of akeyboard, of a tactile interface and/or of a pointing device, such as amouse for example.

According to particular features of the invention, the processing meansare designed to define each trajectory thanks to three-dimensionalanalyses made based on the operating planning parameters and on thespatial coordinates of the resetting elements.

According to another feature of the invention, the tools comprise atleast one contact or contactless probe and/or at least one ultrasonicprobe, and/or at least one rangefinder.

According to another feature of the invention, the probe is a mechanicalpointing instrument designed to be removably fixed on the robot arm. Incooperative mode, the user can point an element on the patient's head bymoving manually the pointing instrument and getting into contact withthe target. Such a probe permits the user to acquire for example thepositions of relevant anatomical points or the positions of radio-opaquemarkers or the positions of a multitude of points in contact with thepatient's skin in order to obtain a surface therefrom by reconstruction.

According to another feature, the probe is a distance measuring opticalmodule, for example a laser rangefinder.

Based on the data from coders of the robot arm, on the geometry of theprobe and on the distance measurement provided by the optical module,the system can calculate the three-dimensional position of the point ofthe object intersected by the laser beam directly in the system ofcoordinates of the robot arm.

In this case, the probe provides a virtual contactless pointingsolution. Analogously to the mechanical pointing instrument, such aprobe permits the user to acquire the positions of relevant anatomicalpoints, of radio-opaque markers or of a multitude of points in contactwith the patient's skin in order to obtain a surface therefrom byreconstruction.

According to another feature of the invention, at least one of the toolsis comprised of a tubular guide or guiding sleeve.

Thanks to these features, the robotized platform equipped with a tubularguide or with a sleeve mounted fastened on the receiving element of thepositioning arm, can be used as stereotaxic frame, the sleeve maintainedin a fixed spatial position by the positioning robot arm offering anaxial guiding for a drill bit, for an electrode, for a needle and otherinstruments and means usable in the frame of stereotaxic neurosurgery.

When the pre-operating images (scanner, MRI or other method) and theposition of the patient are put in correspondence, the system knows theposition of the instrument(s) carried by the robot arm.

Said instrument positioned by the robot arm in correspondence with theplanning can be a laser pointer or other pointer type. The laser pointerthen permits to target on the patient an anatomical structure identifiedon the pre-operating imaging. In cooperative mode (as defined above),the user is capable of pointing a target on the patient's head byseizing, by its terminal portion, the robotized positioning arm equippedwith a laser pointer, and moving it manually. The pointed direction isrepresented on the pre-operating images of the planning console.

The platform, object of this invention, then advantageously substitutesa neuro-navigation system.

The advantage of such a robot arm is that it can maintain the pointer inposition, which is not the case with current neuro-navigation systemswhen the pointer is held manually.

According to another feature of the invention, at least one of the toolsis comprised of a surgical instrument. In this way, the surgical actionwill be performed not by the surgeon but by the robot arm incorrespondence with the planning.

The image recording means is designed to be removably fixed at the endof the robot arm. Said image recording means comprises at least onevideo camera of the digital type, for example.

Thanks to said image recording means, the user can visualize on thepatient a region of interest, for example a region identified on thepre-operating imaging. In cooperative mode, as defined above, the useris capable of visualizing a region of his choice on the patient's headby seizing the positioning arm by its terminal portion and by moving itmanually. The visualized region is represented on the pre-operatingimages of the planning console.

The means for displaying images obtained from the camera can forexample, non-restrictively, be a screen of the type 2D and/or a helmetof the type 2D or even preferably of the type 3D if stereovisiontechniques are used. The platform, object of this invention, thensubstitutes advantageously a navigated surgical microscope. The videostream delivered by the image recording means can be transmittedsimultaneously to the screen of the planning console. Thus, the surgeonand the rest of his team visualize the same video image of theanatomical region during operation. They can be transmitted to anothervisualization means but also, simultaneously, to that othervisualization means and to the screen of the planning console.

Instead of manually moving the image recording means by seizing therobot arm in cooperative mode, the user can also guide the movements ofthe robot arm by means of a control box. The same control box permitsthe regulation of the camera(s) of the image recording means, inparticular the zoom level and the focusing distance. This control boxcan comprise control buttons and/or at least one control lever.

Alternately, the positioning of the image recording means in cooperativemode, i.e. by seizing by its terminal portion the positioning armequipped with said recording means and by moving it manually, can bemade without spatial correspondence at the level of the planningconsole. The platform, object of this invention, is then the equivalentto a simple surgical microscope.

According to another feature of the invention, the means for recordingimages of the field of operation and other relevant anatomical regions,comprises a pair of stereoscopic cameras for example of the digital typein order to acquire two stereoscopic video images of the anatomicalregion to be processed and be able to render a 3D view of the regionthanks to a stereoscopic images visualization system being part of theinvention. The advantage of this method is to render the perception ofthe relief to the surgeon, thus improving the quality of his surgicalaction.

According to another feature of the invention, the image recording meansincludes an optical module designed to be interfaced to an optical cableconnected itself to a cold light source. Thus, the device lights theanatomical region to be processed acquiring at the same time a videostream therefrom.

A well-known disadvantage of certain operating microscopes is that theyrequire a powerful lighting of the anatomical region so that the imagetransmitted in the binoculars has a sufficient luminosity. The use ofvideo cameras of the digital type is a positive advantage since they donot require a powerful lighting. An ambient lighting can then sufficefor a correct vision of the anatomical region.

According to another feature of the invention, the image recording meansincludes two laser modules projecting visible laser beams. Said laserbeams converge on one point which can be adjusted to be the point ofintersection of the two optical axes of the stereoscopic cameras.

These convergent laser modules bring an advantage during the use, sincethey indicate the optimal working area for the perception of the relief.They are also advantageous in production for facilitating the centeringof the two stereoscopic cameras on the same point and determining thegeometry of the image recording means tool.

According to another feature of the invention, the image recording meansincludes a central laser module aligned with the central optical axis ofthe pair of stereoscopic cameras. Said visible laser beam materializesthe axis in which the video image of the anatomical region is acquired.

According to another feature of the invention, the central laser moduleis a rangefinder laser capable of measuring the distance between itsexternal face and the nearest object pointed by the laser beam.

According to another feature of the invention, the image recording meansincludes a mechanical system for rotation around its optical axis. Theuser can thus rotate the image recording means with the help of a handlein order to orient the video image of the anatomical region according tothe needs of its surgical action.

According to another feature, the invention integrates a mechanicalpointer equipped with at least one visible marker, itself well-known,designed to be located on the video images acquired by the imagerecording means. The position of the tip of the pointer can then becalculated by triangulation by identifying the marker(s) on the twostereoscopic images. This calculation requires first a calibration ofeach of the two cameras (intrinsic parameters) as well as calibration ofthe stereoscopic system (position and orientation of one camera withrespect to the other). The advantage of this solution is that the pairof stereoscopic cameras is situated in an area near the anatomicalregion to be processed and that one thus gets rid of the <<line ofsight>> problem common to existing optical localization neuronavigationsystems.

When the pre-operating images (scanner, MRI or other method) and theposition of the patient are put in correspondence, the system knows theposition of the image recording means carried by the robot arm. Thesystem can then advantageously substitute a microscope combined with aneuro-navigation system. The point of interest displayed on theanatomical region and on the pre-operating images of the planningconsole can be for example the point of intersection of convergent laserbeams and/or the point of impact of the central laser beam and/or thepoint in contact with the mechanical pointer equipped with visiblemarkers.

According to another feature of the invention, a stereoscopic imagesvisualization system of the three-dimensional type is provided.

According to a feature of the invention, the stereoscopic imagesvisualization system is comprised of two screens designed to display twovideo images derived from different sources. Said screens canadvantageously be mounted on a helmet or on glasses so that the surgeonkeeps his hands free for his surgical action.

Said visualization system can be used during the intervention planningstage on the console for displaying a realistic view of the 3D virtualobjects; for example, the digital model of the patient established basedon the pre-operating images, or on the planning virtual objects such asa target point, an entry point, a rectilinear trajectory, a surface ofinterest, a volume of interest, etc.

The surgeon thus handles directly data in three-dimensional form, unlikethe existing neuro-navigation systems, which only have a screendisplaying data in two-dimensional form.

The device can also advantageously substitute an operating microscope bydisplaying through the visualization system the video images derivedfrom the image recording means. The surgeon can then operate in theposition he considers optimal for his surgical action.

Once the pre-operating images (scanner, MRI or other method) and theposition of the patient in the operating theater are put incorrespondence, the planning console knows the position of the imagerecording means carried by the robot arm. Knowing a priori theprojective model of the cameras, it is possible to superimpose thevirtual images on the real images in order to display a defined elementof the targeted anatomical region. This element can be for example atumor in case of a tumor resection, or a target point, or an entrypoint, or a trajectory, or an instrument, or even an anatomical regionof interest. The stereoscopic visualization system then displays videoimages of the anatomical region, augmented with planning virtualelements. Then the function of augmented reality is ensured.

Augmented reality permits to provide precious data to the surgeon whilehe is operating. This is a very advantageous function because it permitsthe surgeon to avoid the situation in which he had to look alternatelythe region he was operating and the pre-operating images displayed on ascreen and make the correspondence between said data mentally. All dataare projected in a superimposed manner on the same screen. Thestereoscopic visualization system can display in particular data intextual form, for example distances or volumes.

These features give the platform a multi-application naturecorresponding to the needs of hospital centers in terms of logisticalmanagement and maintenance and meet the objectives of flexibility andversatility of the operating theater.

Another object of this invention is a method aiming at augmenting theprecision of the resetting between the anatomical region to beprocessed, its digital model and a robotized arm.

To this end, the method according to the invention consists in:

acquiring, prior to the neurosurgical intervention, first digital imagesof the region to be processed and transferring said digital images tothe planning console by means of a network or of a physical medium sothat they are recorded and processed therein,

acquiring in the per-operating stage, with the help of a scanninginstrument carried by the element receiving the terminal distal segmentof the robotized arm, second digital images of a pertinent portion of abody area of the patient appearing already on the first digital images,and transferring said second digital images to the planning console sothat they are recorded and processed therein,

building a first three-dimensional digital model based on the firstdigital images, said model showing the patient's pertinent body area,

building a second three-dimensional digital model based on the seconddigital images, still showing the patient's pertinent body area,

and putting in correspondence the first and second models bysuperimposition of the representations of the pertinent body areaappearing on one model and on the other.

Thus, such a method does not require the presence of radio-opaquemarkers and increases the degree of precision of the resetting betweenthe pre-operating model, the patient and the robotized arm.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS

Other advantages and features of the invention will appear while readingthe description of a preferred embodiment given as a non-restrictiveexample referring to the attached drawings, in which:

FIG. 1 is a synoptic view of the platform according to the invention,

FIG. 2 is a perspective view of a platform according to the invention,

FIG. 3 is a detailed view of the platform according to the invention,

FIG. 4 is a schematic view showing an exemplary embodiment of means forimmobilizing the box with respect to the floor, said means being in anunfolded position,

FIG. 5 is a schematic view of an exemplary embodiment of means forfixing the box to a head rest designed for receiving the head of thepatient to be operated,

FIG. 6 is a schematic view of an exemplary embodiment of a contactlessprobe carried by the robot arm,

FIG. 7 is a schematic view of an exemplary embodiment of an imagerecording means,

FIG. 8 is a schematic view of an exemplary embodiment of visualizationmeans of the three-dimensional type,

FIG. 9 is a schematic view of an exemplary embodiment of a mechanicalpointer equipped with a visible marker.

IMPROVED MANNER FOR IMPLEMENTING THE INVENTION

As shown, the multi-application robotized platform for neurosurgery,according to the invention, includes a planning console 1, which can beloaded, comprising processing means 2 capable, in particular, ofreceiving and processing digital images, a robotized positioning arm 3comprising a plurality of arm segments, one of which is terminal andproximal and the other is terminal and distal, said segments beinginterconnected by articulated elements and the terminal distal armsegment comprising a receiving element 5 arranged in such a way as toreceive, in a fixed state, removably, tools 4, instruments, and thelike, said robot arm being guided by the planning console 1.

The platform also comprises a set of tools and possibly surgicalinstruments designed to be positioned and removably fixed to thereceiving element 5 of the terminal distal arm segment as explainedpreviously, as well as a means 14 for recording video images of thefield of operation and means for displaying 6 pre-operating andper-operating images. Said visualization means are electricallyconnected to the planning console for receiving video signals therefromrelated to the images to be displayed, and/or to a means 14 forrecording video images such as a camera.

The visualization means can include visualization means of thethree-dimensional type.

The platform will also be equipped with a control screen 60 and with acommunication interface 61 designed to receive operating planningparameters from a user.

A central unit and a data input computer interface, which can be part ofthe abovementioned communication interface, are associated to thepositioning robot arm 3.

The robotized positioning arm 3, by its terminal proximal segment, isfixed to an orientation turret installed fixedly on the upper portion ofa parallelepipedal box 7. This box contains electronics suitable inparticular for controlling the arm 3.

Between the arm segments of the positioning robot arm 3 are providedarticulated elements, for example six, comprising motors and incrementalcoders associated, at the level of each articulated element, to the axleor to each of the swivel pins defined by the latter. Each motor iscapable of driving into rotation two contiguous segments one withrespect to the other and each associated incremental coder is capable ofproviding information relative to the angular position of one of thesesegments with respect to the other. The articulated elements permit toposition the terminal tool, the instrument and the like, both inposition (three degrees of freedom) and in orientation (three degrees offreedom). The angular values measured by the incremental coders permit,thanks to the known geometry of the robotized arm and to the knowngeometry of the tool, instrument and the like carried by the arm 3, tocalculate the Cartesian position of the distal end of the robotized arm,the Cartesian position of the end of the tool, instrument and the likeand the orientation of the latter in space.

The arm, as described, receives an appropriate fairing so as to have aminimum of nooks in order to avoid the risk of dust or pathogenicelements penetrating and thriving therein.

The box 7 comprises in its lower portion omnidirectional rollingelements 8 such as casters carried each by an omnidirectional mountinghaving a vertical rotation axis. Said casters 8 and mountings ensure aneasy movement on the ground.

The box 7 comprises means for immobilization with respect to the floorso as to prevent its movement during the surgical intervention.

According to a first embodiment, these immobilization means arecomprised of blocking elements, well-known per se, associated to thecasters 8 and to the mountings, when they are activated, prevent therotation of the casters around their natural axis of rotation and thepivoting of the mounting around the vertical axis. The box is thusimmobilized with respect to the floor.

According to a variant embodiment, as shown in FIG. 4, the means forimmobilizing the box 7 with respect to the floor are comprised of atleast three feet 70 that can occupy either a retracted positionaccording to which they are placed away from the floor, or an unfoldedposition according to which they are placed in contact with the floor inorder to immobilize the box, each foot 70 being moved from one positionto the other by a driving mechanism 71.

According to a particular embodiment, each foot is formed by theterminal portion of the rod of a hydraulic single-action jack associatedto an appropriate hydraulic circuit 72 common to different jacks,comprising in particular, as well known, at least one hydraulicdistributor and a hydraulic pump driven by an electric motor guided by aremote control. The distributor or each distributor will be electricallycontrolled, for example. The motor 71 can also be formed of an electricjack.

Thus, the user can let the feet 70 down in order to stabilize the box 7,without exerting any particular effort.

The box 7 can be provided with means for fixing to a surgical table onwhich the patient to be operated has been placed beforehand, the head Hof the latter being maintained firmly in an appropriate position by ahead rest that is fixed with respect to the table.

The means for fixing the box 7 to the operating table prevent anymovement of the box with respect to said table and are comprised of twomounting flanges 9 capable of cooperating, each, in a fixed state withone of the rails of the table, each flange being brought adjustably inposition by a support structure 10 integral with a support rail 11carried by one of the sides of the box 7. The shape and dimensions ofeach mounting flange 9 are compatible with those of the rails of thetable. Each support structure 10 is formed of a vertical arm 10 areceiving the corresponding mounting flange 9. This flange 9 is mountedwith a possibility for movement in height along the vertical arm 10 aand comprises a tightening element such as a compression screw or thelike, for immobilization on the arm 10 a according to the appropriateposition. Each support structure also has a horizontal arm 10 b fixed tothe vertical arm 10 a. This horizontal arm 10 b comprises a secondvertical arm 10 c introduced in a slide mounted adjustably in positionin the support rail 11 of the box 7. This second vertical arm will beimmobilized in the slide by means of a screw, which also ensures theimmobilization of the slide in the support rail 11.

According to another embodiment, as shown in FIG. 5, the box 7 is nolonger fixed to the operating table T, but directly to a head rest 15designed for receiving the head H of the patient to be operated, thelatter being placed on the operating table T. This box 7 is connected tothe head rest 15 through specific fixing means ensuring, when it isactivated, a rigid link between the box 7 and the head rest 15. Thisarrangement has the advantage of being rid of the flexibility of theoperating table T. These fixing means can be placed in a so-calledinactive state permitting the appropriate positioning of the box 7 withrespect to the head rest 15.

As a non-restrictive example, this means can be formed of an articulatedmechanical arm 16, comprised of several arm segments 16a connected twoby two by articulated elements 16 b associated to immobilizationflanges, not shown, that can each occupy either a locked position of theassociated articulated element or an unlocked position of the latter.

As mentioned above, a central unit 30 and a data input computerinterface 32 are associated to the positioning robot arm 3.

The central data unit 30 can be placed in the box and be part of theelectronics the latter transports.

The robotized platform can also include a contact or contactless probe.

The contact probe can be formed of a mechanical pointer carried by theterminal distal segment of the robot arm. Said mechanical pointerdesigned to be brought into contact with the target to be acquired caninclude a pointing ball or a dry point.

A contactless probe 17 formed of a distance measuring optical modulesuch as, for example, a laser rangefinder, is schematically shown inFIG. 6 in association with a robot arm 3. One can see in this Figurethat said probe 15 is carried by the terminal distal segment of therobot arm and is oriented toward a characteristic point of the head H ofthe patient.

The image recording means 14 comprises at least one video camera of thedigital type, for example. In a preferred embodiment, as shown in FIG.7, the means for recording images of the field of operation comprises,on a support plate 140, two stereoscopic cameras 141, for example of thedigital type, in order to acquire two stereoscopic video images of theanatomical region to be processed and so as to be able to render a 3Dview of said region thanks to a stereoscopic image visualization systemas described below. It should be noted that said two cameras 141 arearranged symmetrically with respect to the central optical axis AA′.

Said image recording means is in addition provided with an opticalmodule 142 designed to be interfaced to an optical cable 143 itselfconnected to a cold light source 142 a in order to light the anatomicalregion to be processed.

According to an advantageous arrangement of the invention, the imagerecording means 14 comprises two laser modules 143 lateral with respectto the cameras 141 and preferably arranged symmetrically with respect tothe optical axis AA′. Said laser modules 143 project visible laser beamsand are oriented so that their beams converge on a point that can beadjusted to be the point of intersection of the two optical axes of thestereoscopic cameras. As shown, the point of convergence belongs to theoptical axis AA′.

These convergent laser modules 143 offer an advantage during the use,since they indicate the optimal working area for the perception of therelief. They are also advantageous in production for facilitating thecentering of the two stereoscopic cameras on the same point anddetermining the geometry of the image recording means tool.

The image recording means 14 comprises, in addition, a central lasermodule 144 aligned with the central optical axis AA′. This visible laserbeam materializes the axis in which the video image of the anatomicalregion is acquired.

The laser module 144 is a rangefinder laser capable of measuring thedistance between its external face and the nearest object pointed by thelaser beam.

The image recording means 14 can include a mechanical system forrotation about its optical axis AA′ permitting the orientation of thevideo image formed on the visualization means.

Such a rotation system can be made by means of a pivot link or pivotsliding with the whole of the elements described above, integral with ashaft 145 introduced with adjustment sliding in the through bore of asheath 147 provided with a support 148 for removable fastening to thereceiving element 5 of the terminal distal segment of the robotized arm.This shaft 145 can be fixed rigidly to the plate 140.

Externally to the sheath 146, the shaft 145 will receive a handle forpivotal operating 147 through an action on which the image recordingmeans 14 can be oriented appropriately. A tightening mechanism with jawsfor example, not shown, can be attached to the sheath 146, designed toexert a tightening effort on the shaft 145 when it is activated in orderto prevent any pivoting movement of the recording means 14 with respectto the sheath 146. This jaw mechanism can be made inactive by acting ona control installed on the handle 147. When inactive, said tighteningmechanism permits the pivoting of the recording means 14 with respect tothe sheath 146.

FIG. 8 represents an exemplary embodiment of visualization means 18 ofthe three-dimensional type. This stereoscopic visualization means,designed to be carried by the surgeon, includes a helmet 180 designed tobe inserted onto the head of the surgeon and two visualization screens181 that can be positioned in front of the eyes of the surgeon. Thevisualization screens can display video images of the anatomical regionto be processed, possibly enriched with virtual elements of the planningin order to ensure an augmented reality functioning.

FIG. 9 represents a mechanical pointer 19 equipped with at least onevisible marker 20, designed to be located on the video images acquiredby the image recording means. It can be seen in this Figure that themarker 20 comprises strongly contrasting areas in this particular casewhite areas and black areas. Thanks to the marker 20 the spatialposition of the tip of the pointer 19 can be calculated by triangulationby identifying the marker on the two stereoscopic images provided by thetwo video cameras of the image recording means 14.

The robotized platform object of this invention permits the positioningof a guide, of a probe or of a video image recording means. Itsutilization is based on four stages:

a first stage of acquiring digital images (scanner or MRI) of the regionto be processed and transferring these digital images to the planningconsole 1 by means of a network or of a physical medium,

a second stage of processing said images, identifying the anatomicalstructures and planning the surgical action, for example the definitionof an entry point and of a target point for establishing a trajectory ofa biopsy needle,

a third stage of putting in correspondence the pre-operating images withthe position of the patient's head in per-operating phase according toone of the embodiments described below,

and finally a last stage of automatic positioning of a terminal tool 4,for example a guide, a laser pointer, a camera, a capturing device andthe like.

The robotized platform according to the invention takes up the samehypotheses regarding the sagging of the brain and the possible flexionof the needles, as well as the stereotaxic frames, the neuro-navigationsystems and the robotic systems.

The pre-operating images can be put in correspondence with the positionof the patient in the operating theater in several ways thanks to thedifferent technologies integrated in the platform.

According to a first embodiment, the resetting method resorts toradio-opaque markers.

During the intervention, the pre-operating images (scanner or MRI orother method) can be put in correspondence with the position ofpatient's head thanks to markers designed to be located on the imaging,for example radio-opaque markers. In this case, said markers are placedon patient's head prior to the acquisition of the pre-operating images.They are identified on the images during planning stage in order todetermine their position in the image mark (automatically with apossibility of a manual retouching).

During the intervention, the surgeon places the robotized positioningarm in cooperative mode and manually moves said positioning robot armequipped with a probe in order to locate the positions of the differentmarkers in the robot mark. Once the positions of markers in the imagemark and in the robot mark are known, a point-by-point resettingalgorithm permits to put the two marks in correspondence.

This method can be implemented with different types of probe: themechanical pointing instrument and the virtual contactless probe (laserrangefinder).

Alternately, the surgeon places the robot arm equipped with the imagerecording means 14 above the head of the patient. The surgeon can thenmanually proceed to the detection of the radio-opaque markers by usingthe mechanical pointer 19 equipped with black and white visible markers20. The system can also proceed automatically to the detection of theradio-opaque markers by positioning the image recording means 14 indifferent positions around the head H of the patient, acquiringstereoscopic images containing radio-opaque markers, segmenting theimages for locating the radio-opaque markers and calculating bytriangulation of their three-dimensional positions in the system ofcoordinates of the robot arm. In order to facilitate the detection ofthe radio-opaque markers, specific markers having a strong contrast inthe visible spectrum can be used.

Once the positions of the markers in the image mark and in the robotmark are known, a point-by-point resetting algorithm permits to put thetwo marks in correspondence.

According to another embodiment, the method does not resort toradio-opaque markers.

Alternatively, the putting in correspondence of the image and robotmarks is made based on anatomical surface marks instead of markers.During the intervention, the surgeon manually moves the positioningrobot arm equipped with a probe in order to locate the positions ofcharacteristic anatomical points or surfaces such as the nose, arches,ears, teeth or other. A dots-surface or surface-surface resettingalgorithm permits to reset the dots or surfaces thus acquired with thepre-operating examinations.

This method can be implemented with different types of probe: themechanical pointing instrument, the virtual contactless probe (laserrangefinder), the mechanical pointer equipped with black and whitevisible markers.

This method for putting in correspondence has the advantage of notrequiring any installation of markers on patient's head prior to theimaging.

According to the method explained above, the robot arm is manually movedby the surgeon.

Alternatively, the acquisition of characteristic anatomical surfaces ismade contactless and automatically, by scanning the whole or portion ofthe head H of the patient. Such an acquisition can be obtained by acontactless measuring sensor 4 for example a laser rangefinder, fixed atthe end of the positioning robot arm 3. Said robot arm automaticallyscans the region of interest by driving said sensor 4 according to anappropriate movement in front of said region of interest, for example,at constant speed according to a rectilinear translation movement.Knowing the exact position of the sensor 4 in the robot mark permits thereconstruction of anatomical surfaces.

This method can also be implemented with the image recording means whenit comprises a laser rangefinder. This is particularly advantageousduring a navigated microscopy procedure, because it is no longernecessary to change the tool during the intervention.

An echographic probe can also be used instead of the contactlessmeasuring sensor. In this case, the putting in correspondence of theimage and robot marks can be made thanks to a processing algorithm basedon the properties of the image such as intensity, gradient, and otherproperties.

These automatic methods for putting in correspondence do not require anymanual intervention by the surgeon.

Once the putting in correspondence is done, the robot automaticallypositions the tool attached to the receiving element on the plannedtrajectory.

It stands to reason that this invention can receive all variants withinthe field of technical equivalents without however departing from thescope of this patent as defined by the claims below.

1.-20. (canceled)
 21. Multi-application robotized platform forneurosurgery, wherein the platform comprises: a planning consolecomprising processing means capable, in particular, of receiving andprocessing digital images, a positioning robot arm comprising aplurality of arm segments, one of which is terminal and proximal and theother is terminal and distal, said segments being interconnected byarticulated elements and the terminal distal arm segment comprising areceiving element arranged in such a way as to receive tools, said robotarm being guided by the planning console, at least one means forrecording video images capable of recording images of the anatomicalregion to be processed, said means being electrically connectable to theprocessing means the planning console includes, and said recording meansbeing capable of being positioned and removably fixed to the receivingelement of the distal arm segment, said means for recording video imagescomprising a central optical axis (AA′) and integrating a central lasermodule aligned with the central optical axis (AA′), said central lasermodule being a rangefinder laser capable of measuring the distancebetween its external face and the nearest object pointed by the laserbeam, tools, instruments, and the like, designed to be positioned andremovably fixed to the receiving element of the terminal distal armsegment, means for displaying pre-operating and per-operating images,said means being electrically connected to the planning console forreceiving video signals therefrom relating to the images to bedisplayed, and/or to the image recording means.
 22. Platform accordingto claim 21, wherein a central unit and a data input computer interfaceare associated to the positioning robot.
 23. Platform according to claim21, wherein the positioning robot arm has at least six degrees offreedom i.e. three translations and three rotations.
 24. Platformaccording to claim 21, wherein the robot arm comprises a force sensorand is designed to operate according to a mode in which a user can movethe robot arm manually by seizing it by its terminal portion. 25.Platform according to claim 21, wherein the platform is equipped with acontrol screen and with a communication interface designed to receiveoperating planning parameters from a user.
 26. Platform according toclaim 21, wherein the processing means are designed to define eachtrajectory thanks to three-dimensional calculations made based on theoperating planning parameters and on the spatial coordinates of theanatomical marks.
 27. Platform according to claim 21, wherein the toolscomprise at least one guide, and/or at least one mechanical pointer,and/or at least one laser pointer, and/or at least one ultrasonic probe,and/or at least one rangefinder.
 28. Platform according to claim 21,wherein the tools comprise at least one surgical instrument. 29.Platform according to claim 21, wherein the robotized positioning arm,through its terminal proximal segment, is fixed to an orientation turretinstalled fixedly on the upper portion of a parallelepipedal boxcomprising elements for rolling on the floor and means forimmobilization with respect to the latter.
 30. Platform according toclaim 29, wherein the box is provided with means for fixing to theoperating table preventing any movement of the box with respect to saidtable.
 31. Platform according to claim 29, wherein the box comprisesrigid means for fixing to a head rest installed on the head (H) of apatient carried by the operating table (T).
 32. Platform according toclaim 21, wherein the means for recording video images of the anatomicalregion to be processed includes two stereoscopic cameras in order toacquire two stereoscopic video images of the anatomical region to beprocessed and that the visualization means comprise a stereoscopicimages visualization system.
 33. Platform according to claim 32, whereinthe image recording means comprises an optical module designed to beinterfaced to an optical cable itself connected to a cold light source.34. Platform according to claim 32, wherein the image recording meanscomprises two laser modules projecting visible laser beams convergent ona point capable of being adjusted so as to be the point of intersectionof the two optical axes of the stereoscopic cameras.
 35. Platformaccording to claim 32, wherein the image recording means comprises acentral laser module by rotation according to its optical axis AA′. 36.Platform according to claim 21, wherein on the or at least one of thevisualization means are displayed video images of the anatomical regionto be processed augmented with virtual elements in order to ensure anaugmented reality functioning.
 37. Method for resetting the anatomicalregion to be processed with respect to its digital model and a robotizedarm using a platform according to any of the preceding claims, whereinthe method consists in: acquiring, prior to the neurosurgicalintervention, first digital images of the region to be processed andtransferring these digital images to the planning console by means of anetwork or of a physical medium so that they are recorded and processedtherein, acquiring in per-operating stage, with the help of a scanninginstrument carried by the element receiving the terminal distal segmentof the robotized arm, second digital images of a pertinent portion of abody area of the patient appearing already on the first digital images,and transferring these second digital images to the planning console sothat they are recorded and processed therein, building a firstthree-dimensional digital model based on the first digital images, saidmodel showing the patient's pertinent body area, building a secondthree-dimensional digital model based on the second digital images,still showing the patient's pertinent body area, and putting incorrespondence the first and second models by superimposition of therepresentations of the pertinent body area appearing on one model and onthe other.
 38. Resetting method according to claim 37, wherein datadelivered by the rangefinder laser and by the two cameras of the imagerecording means are used for building the second digital model.